Has anyone had experience with parts quality for your 430 when buying from Amazon? Ive been having trouble with a P0134 code referring to the 02 sensor circuit having no activity. Bought a replacement sensor from Amazon a lil while back thinking it will cure my problem. Nope! Code came back so i started looking elsewhere for other possible problems such as broken wires, vacuum and exhaust leaks. Did have the infamous heat shield exhaust leak, got it repaired but still got the code returning. After weeks of probing around, it brought me back to the 02 sensor again. Tested it using a DMM this morning to find its putting out a high voltage reading(+900mV) after warm up. After driving to work, i took another reading while the car was parked idling and got less than 100mV. Bad part i assume. The part i bought is a Denso Oem replacement 02 sensor which is who i believe makes the OEM part. What are the chances of a new 02 sensor being bad right out of the package? Should i go with a different brand? Any thoughts?

 

Really hard to say. You cant measure and test an O2 sensor with a multimeter. O2 sensors fluctuate constantly between 0 and 1 volt.. (usually from .1 to .9). A multimeter may register the voltage, but it is not quick enough to see the fluctuations. You need a scope to proper test it. I also only really trust parts out of a Toyota/Lexus box.. sure, you may get a good deal, and it may even be from the same manufacturer, but who knows if it got rattled around in shipping. Also, i hate to ask, but are you sure you replaced the correct sensor? P0134 refers to bank 1 sensor 1.. ive seen people mistakenly replace bank 2 sensor 1.

 

Actually later that eve i tested the sensor with an Oscope. Still got a steady voltage of around 900mV with no flucuations on the read out. I didnt see a sine wave. Just a steady, straight line. Voltage did drop very slightly when i pressed the gas but not much. Yes im on bank 1 sensor1. Now, i did take a reading of Bank 2 sensor 1 just to be curious and got a steady voltage of around 800mV with no flucuations. Voltage did dip all the way to less than 100mV when the gas was pressed and the voltage took more than a few seconds to get back up to where it was(800mV). Im really stomped now.

 

Your readings sound perfect for a rear O2 sensor... You are testing the O2 sensor that is ahead of the catalytic converter, near the rear of the exhaust manifold, correct? Its pretty tough to get to.. Those reading make no sense for a forward sensor, but a rear, they make perfect sense.

 

Both readings are for the two front sensors.

 

I bought two air filters from amazon. but then again how can they really screw up an air filter, why not pay the extra $$$ for oem parts, imo its definitely worth it